Low-temperature jet mill for high-flowability nylon powder

Abstract

The utility model provides a kind of low-temperature airflow pulverizing device of high flowability nylon powder, belong to low-temperature airflow pulverizing device technical field, including airflow pulverizing device main body, cyclone separator, bag type dust collector, first jacket, external circulation cooling machine, feed pipe, second jacket, gas-gas heat exchange component, spiral flow guide passage;First jacket is set on the outer wall of airflow pulverizing device main body, and first jacket input, output end is connected with external circulation cooling machine to carry out cycle refrigeration, concentrated heat generated in the pulverizing cavity is directly taken away by first jacket, airflow pulverizing device main body feed inlet is connected with feed pipe for feeding, and the outer wall of feed pipe is pre-cooled by second jacket to the feed, to better carry out the cooling of nylon material, the cold source used by second jacket is provided after the heat exchange of residual cold quantity in exhaust pipe, which is connected between cyclone separator and bag type dust collector, by gas-gas heat exchange component, realize the rational use of energy.

Description

Technical Field

[0001] This utility model belongs to the technical field of low-temperature airflow pulverizing devices, specifically relating to a low-temperature airflow pulverizing device for high-flow-rate nylon powder. Background Technology

[0002] The descriptions in this section provide background information relevant to this disclosure only and do not constitute prior art.

[0003] Nylon materials have relatively low glass transition temperature and melting point, making them sensitive to heat. In traditional airflow pulverizers, the collisions and friction between the high-speed airflow and the material, between the material and the inner wall generate a large amount of heat, causing the nylon powder temperature to rise. This makes the powder soft and sticky, adhering to and agglomerating on the inner wall of the pulverizing chamber and pipes, causing equipment blockage, unstable operation, low powder output, reduced yield, and poor flowability of the finished powder. This directly affects the powder spreading performance and process stability of subsequent applications such as 3D printing and powder coatings. Existing cooling methods simply use gas cooling at the air inlet, which has limited effectiveness and cannot quickly remove the concentrated heat generated in the pulverizing chamber. Utility Model Content

[0004] The purpose of this invention is to provide a low-temperature airflow pulverizing device for high-flow-rate nylon powder, which has the advantages of removing frictional heat in real time and efficiently in the core pulverizing area, ensuring that the powder is always pulverized within the "brittle temperature range", making rational use of energy and avoiding waste. It solves the technical problem that the existing cooling method simply uses gas cooling at the air inlet, which has limited effect and cannot quickly remove the concentrated heat generated in the pulverizing chamber.

[0005] This invention provides a low-temperature airflow pulverizing device for high-flow-rate nylon powder, comprising a main body of the airflow pulverizing device, the output end of which is sequentially connected to a cyclone separator and a bag filter. The main body of the airflow pulverizing device is fitted with a first jacket at the upper end of its outer wall. The first jacket's input and output ends are fixedly connected to an external circulating cooler; The upper end of the feed inlet of the main body of the airflow pulverizing device is fixedly connected to a feed pipe, and a second jacket is fitted on its outer wall. The connecting pipe between the cyclone separator and the bag filter is equipped with a gas-to-gas heat exchange component, the output end of which is fixedly connected to the input end of the second jacket. Both the first and second jackets have spiral flow channels inside their cavities.

[0006] As a further optimization, in order to force the cooling medium to flow at high speed along the spiral path without dead zones, significantly increase the flow rate and heat exchange time, and improve the overall heat transfer coefficient, the first jacket and the second jacket have the same structure. The first jacket includes: The jacketed housing has a spiral partition fixed coaxially to its inner wall; The spiral partitions divide the inner cavity of the jacket housing into spiral flow channels.

[0007] As a further optimization, in order to expand the size of the inner cavity of the jacket shell by connecting the cavity protrusion with the inner cavity of the jacket shell, and extend to the inside of the airflow pulverizing device body to actively cool the material, the outer wall of the airflow pulverizing device body is recessed inward to form a cavity protrusion corresponding to the jacket shell, and the cavity protrusion is connected to the jacket shell. The jacket housing is provided with sealing structures between its upper and lower ends and the outer wall of the airflow pulverizing device body; The cavity protrusions are evenly distributed on the outer wall of the main body of the airflow pulverizing device.

[0008] As a further optimization, in order to reduce material adhesion to the main body of the airflow pulverizer and the inner wall of the cavity protrusion, both the main body of the airflow pulverizer and the inner wall of the cavity protrusion are coated with a wear-resistant, hydrophobic, and oleophobic coating, specifically a Teflon coating.

[0009] As a further optimization, to ensure the sealing of both ends of the first and second jackets, and to create a new jacket inner cavity by connecting the jacket shell with the protruding inner cavity of the cavity for the circulation of the refrigerant, the sealing structure includes: The retaining ring is welded to the upper and lower sides of the outer wall of the main body of the airflow pulverizer. The retaining ring is tightly fitted to the end of the jacket housing on the same side; An annular groove is provided at the interface of the retaining ring, the jacket housing and the outer wall of the main body of the airflow pulverizing device on the same side, and a sealing rubber ring is inserted in it. The sealing ring is located within the annular groove and is in an elastically compressed state.

[0010] As a further optimization, in order to utilize the residual cold energy in the discharge through gas-to-gas heat exchange to pre-cool the feed from the feed pipe, the gas-to-gas heat exchange assembly includes: The gas-to-gas heat exchanger has its tube side inlet and outlet connected in series to the connecting pipe between the cyclone separator and the bag filter. The shell-side inlet of the gas-to-gas heat exchanger is connected to an external fan as a gas source. The shell-side outlet of the gas-to-gas heat exchanger is fixedly connected to a connecting pipe, the end of which is fixedly connected to the input end of the second jacket.

[0011] As a further optimization, in order to more fully recover and utilize the cold energy in the exhaust gas through the series design of multiple gas-to-gas heat exchangers, the number of gas-to-gas heat exchangers is at least two, and the gas-to-gas heat exchangers are connected in series. The shell-side inlet of the gas-to-gas heat exchanger is fixedly connected to an air inlet manifold, and the air inlet manifold is connected to an external fan as an air source. The shell-side outlet of the gas-to-gas heat exchanger is fixedly connected to a main air outlet pipe, and the main air outlet pipe is fixedly connected to a connecting pipe.

[0012] As a further optimization, in order to minimize the conduction of heat from the external environment inward, prevent condensation and icing on the outer surface of the cooling jacket, improve system energy efficiency and safety, and allow the cooling system to focus on handling internal frictional heat, the outer wall of the jacket shell is wrapped with an insulation material layer, specifically an aerogel felt layer.

[0013] This utility model provides a low-temperature airflow pulverizing device for high-flow-rate nylon powder, which has the following improvements and advantages compared with the prior art: A first jacket is installed on the outer wall of the main body of the airflow pulverizer. The input and output ends of the first jacket are connected to an external circulating cooler for circulating cooling. The concentrated heat generated in the pulverizing chamber is directly removed through the first jacket. The feed inlet of the main body of the airflow pulverizer is connected to a feed pipe for feeding. The outer wall of the feed pipe is pre-cooled by a second jacket to better cool the nylon material. The cold source used by the second jacket is the residual cold energy in the exhaust pipe connecting the cyclone separator and the bag filter, which is provided after heat exchange by the air-to-air heat exchange component, so as to realize the rational use of energy and avoid waste. Attached Figure Description

[0014] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0015] In the attached diagram: Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic cross-sectional view of the structure of the first jacket of this utility model; Figure 3 This utility model Figure 2 Enlarged structural diagram at point A in the middle; Figure 4 This is a schematic cross-sectional view of the thermal insulation material layer assembly structure of this utility model; Figure 5 This is a schematic diagram of the gas-to-gas heat exchange component of this utility model.

[0016] Explanation of reference numerals in the attached figures: 1-Main body of airflow pulverizer, 2-Second jacket, 3-First jacket, 31-Jacket shell, 32-Cavity protrusion, 33-Spiral baffle, 34-Wear-resistant hydrophobic and oleophobic coating, 35-Insulation material layer, 4-External circulating cooler, 5-Cyclone separator, 6-Bag dust collector, 7-Air-to-air heat exchange component, 71-Air-to-air heat exchanger, 72-Outlet main pipe, 73-Connecting pipe, 74-Inlet main pipe, 8-Feed pipe, 9-Sealing structure, 91-Baffle ring, 92-Annular groove, 93-Sealing rubber ring. Detailed Implementation

[0017] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented by various different embodiments as defined and covered by the claims.

[0018] In the following description of this utility model, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and "vertical" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] In the following description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; or they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] Furthermore, in the following description of this utility model, unless otherwise stated, "multiple", "multiple groups", or "multiple roots" means two or more.

[0021] Please see Figure 1-5 The present invention provides a technical solution: a low-temperature airflow pulverizing device for high-flow nylon powder. The low-temperature airflow pulverizing device mainly includes an airflow pulverizing device body 1, a cyclone separator 5, and a bag filter 6. The output end of the airflow pulverizing device body 1 is fixedly connected to the cyclone separator 5 and the bag filter 6 in sequence to form a complete material pulverizing, separation and collection process.

[0022] To achieve efficient cooling, a first jacket 3 is installed on the upper part of the outer wall of the air jet pulverizer body 1. Its input and output ends are fixedly connected to an external circulating cooler 4 through pipes to form an active circulating refrigeration system. A feed pipe 8 is fixedly connected to the upper part of the feed inlet of the air jet pulverizer body 1. A second jacket 2 is installed on the outer wall of the feed pipe 8. An air-to-air heat exchange component 7 is installed on the connecting pipe between the cyclone separator 5 and the bag filter 6. The output end of the air-to-air heat exchange component 7 is fixedly connected to the input end of the second jacket 2 through a pipe to pre-cool the feed through the feed pipe 8. The inner cavities of the first jacket 3 and the second jacket 2 are both designed with spiral flow guide channels to optimize the flow and heat exchange of the cooling medium.

[0023] Furthermore, the second jacket 2 uses the residual cold energy in the exhaust pipe connecting the cyclone separator 5 and the bag filter 6 as the cold source, which is then provided after heat exchange through the gas-to-gas heat exchange component 7, to achieve rational use of energy and avoid waste.

[0024] like Figure 2 As shown, the first jacket 3 and the second jacket 2 adopt the same preferred structure. Taking the first jacket 3 as an example, it includes a jacket shell 31 sleeved on the outer wall of the airflow pulverizing device body 1. On the inner wall of the jacket shell 31, a spiral baffle 33 is coaxially fixed. This spiral baffle 33 divides the inner cavity of the cylindrical jacket shell 31 into a continuous and single spiral flow channel. The cooling medium enters from the inlet at the lower end of the jacket and is forced to flow upward spirally along the channel formed by the spiral baffle 33, and finally flows out from the outlet at the upper end of the jacket. This design eliminates the flow dead zone and significantly increases the flow and residence time of the cooling medium in the jacket, thereby greatly improving the heat exchange efficiency with the wall of the airflow pulverizing device body 1.

[0025] To further enhance the cooling effect, multiple cavity protrusions 32 are formed inward on the outer wall of the airflow pulverizer body 1, corresponding to the area covered by the jacket shell 31. The inner cavity of these cavity protrusions 32 is directly connected to the inner cavity of the jacket shell 31. When the cooling medium flows in the spiral guide channel, it can partially enter these cavity protrusions 32. These cavity protrusions 32 are evenly distributed in a circle on the outer wall of the airflow pulverizer body 1. They extend into the pulverizing chamber like "cooling fins", which can cool the high-speed moving material and the frictional heat generated in the pulverizing chamber more directly and actively, and fundamentally suppress the temperature rise inside the chamber.

[0026] Understandably, the outer wall of the feed pipe 8 also has the same structure as the cavity protrusion 32.

[0027] like Figure 2 and Figure 3As shown, to ensure the sealing and durability of the jacket, a reliable sealing structure 9 is provided between the upper and lower ends of the jacket housing 31 and the outer wall of the airflow pulverizing device body 1. This structure includes retaining rings 91 welded to the upper and lower sides of the outer wall of the airflow pulverizing device body 1. During installation, the end of the jacket housing 31 is tightly fitted with the retaining ring 91 on the same side. In addition, an annular groove 92 is provided at the interface where the retaining ring 91, the end face of the jacket housing 31 and the outer wall of the airflow pulverizing device body 1 meet. A sealing rubber ring 93 is embedded in the groove. After installation, the sealing rubber ring 93 is in an elastically compressed state in the annular groove 92, thereby ensuring that the two ends of the jacket remain tightly sealed when subjected to internal fluid pressure. This makes the inner cavity of the jacket housing 31 and the inner cavity of the cavity protrusion 32 together form a closed cavity for the circulation of cooling medium.

[0028] Furthermore, to prevent the low-temperature nylon powder from adhering to the cooled container wall, a wear-resistant, hydrophobic, and oleophobic coating 34 is sprayed onto the inner wall of the main body 1 of the airflow pulverizer and the inner wall surface of all cavity protrusions 32.

[0029] In a preferred embodiment, the coating is Teflon; in other embodiments, the wear-resistant, hydrophobic, and oleophobic coating 34 may also be a polytetrafluoroethylene (PTFE) coating.

[0030] Understandably, the inner walls of other pipes and the classifying wheel of the main body 1 of the airflow pulverizing device in the scheme are all coated with a layer of wear-resistant, hydrophobic and oleophobic coating 34 to prevent adhesion. This coating can effectively reduce material sticking to the wall, maintain powder flowability, and extend the equipment cleaning cycle.

[0031] like Figure 4 As shown, in order to minimize the transfer of ambient heat into the cooling system, prevent condensation or ice formation on the outer surface of the jacket due to excessively low temperature, and improve system energy efficiency, a layer of thermal insulation material 35 is wrapped around the outer wall of the jacket shell 31.

[0032] In a preferred embodiment, the insulation material layer 35 is a high-performance aerogel felt layer with extremely low thermal conductivity, which can effectively isolate heat exchange.

[0033] like Figure 1 and Figure 5As shown, the tube-side inlet and outlet of the heat exchanger 71 in the gas-to-gas heat exchange assembly 7 are connected in series on the pipe between the outlet of the cyclone separator 5 and the inlet of the bag filter 6. In this way, the exhaust gas, which is still at a low temperature after crushing and cyclone separation, will flow through the tube side of the heat exchanger 71. At the same time, ambient temperature air from an external fan is introduced into the shell-side inlet of the gas-to-gas heat exchanger 71 as the air source. Inside the heat exchanger, the low temperature exhaust gas and ambient temperature air undergo indirect heat exchange. The cold energy in the exhaust gas is recovered and used to cool the air in the shell side. The cooled air flows out from the shell-side outlet of the gas-to-gas heat exchanger 71 and is transported to the input end of the second jacket 2 through a connecting pipe 73, serving as a cold source for pre-cooling the nylon material flowing through the feed pipe 8. This design realizes the recycling of waste cold energy, saving energy and reducing consumption.

[0034] like Figure 5 As shown, to further recover energy, the number of gas-to-gas heat exchangers 71 can be set to two or more, connected in series. The shell-side inlets of multiple series-connected heat exchangers 71 are connected to a common inlet duct 74, which connects to an external fan. The shell-side outlets are connected to a common outlet duct 72, which is then connected to the second jacket 2 via a connecting pipe 73. The series design increases the heat exchange area and flow path, enabling more complete extraction and utilization of the cold energy in the exhaust.

[0035] Understandably, the connecting pipe 73 is made of a material with low thermal conductivity, such as polyurethane, to reduce the loss of cold energy during transportation. The exhaust of the second jacket 2 is either directly discharged into the air or discharged after further treatment.

[0036] Brief description of the working process: The external circulating cooler 4 drives the low-temperature cooling medium to circulate in the first jacket 3, directly and efficiently removing the concentrated heat generated by the collision and friction of the material in the crushing chamber of the main body 1 of the airflow pulverizer, keeping the core crushing area within the brittle temperature range of the nylon material. At the same time, the low-temperature exhaust gas discharged from the cyclone separator 5 flows through the air-to-air heat exchange component 7 before entering the bag filter 6. The coldness in the exhaust gas is recovered by the heat exchanger and used to cool the fresh air entering the shell side of the heat exchanger. This pre-cooled air is then sent into the second jacket 2 to pre-cool the nylon raw material entering from the feed pipe 8. Through the dual cooling mechanism of active cooling in the core area and pre-cooling of the feed combined with waste cold recovery, the problems of softening, adhesion, agglomeration and decreased fluidity of nylon powder caused by temperature rise during airflow pulverization are effectively solved, ensuring stable operation of the equipment and high quality of the product, while realizing the rational use of energy.

[0037] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A low-temperature airflow pulverizing device for high-flow-rate nylon powder, comprising an airflow pulverizing device body (1), wherein a cyclone separator (5) and a bag filter (6) are sequentially and fixedly connected to its output end, characterized in that, The main body of the airflow pulverizing device (1) has a first jacket (3) fitted on the upper end of its outer wall. The input and output ends of the first jacket (3) are fixedly connected to the external circulating cooler (4); The upper end of the feed inlet of the main body (1) of the airflow pulverizing device is fixedly connected to the feed pipe (8), and the outer wall of the device is equipped with a second jacket (2). The gas-to-gas heat exchange assembly (7) is installed on the connecting pipe between the cyclone separator (5) and the bag filter (6), and its output end is fixedly connected to the input end of the second jacket (2). Both the first jacket (3) and the second jacket (2) have spiral guide channels in their inner cavities.

2. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 1, characterized in that, The first jacket (3) and the second jacket (2) have the same structure. The first jacket (3) includes: The jacket housing (31) has a spiral partition (33) fixed coaxially on its inner wall. The spiral partition (33) divides the inner cavity of the jacket housing (31) into spiral flow channels.

3. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 2, characterized in that, The outer wall of the main body (1) of the airflow pulverizing device is recessed inward to form a cavity protrusion (32) corresponding to the jacket shell (31), and the cavity protrusion (32) is connected to the jacket shell (31); The jacket housing (31) is provided with sealing structures (9) between its upper and lower ends and the outer wall of the airflow pulverizing device body (1). The cavity protrusions (32) are evenly distributed around the outer wall of the main body (1) of the airflow pulverizing device.

4. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 3, characterized in that, The main body (1) and the inner wall of the cavity protrusion (32) of the airflow pulverizing device are both coated with a wear-resistant, hydrophobic and oleophobic coating (34).

5. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 3, characterized in that, The sealing structure (9) includes: The retaining ring (91) is welded to the upper and lower sides of the outer wall of the main body (1) of the airflow pulverizing device; The retaining ring (91) is tightly fitted to the end of the jacket housing (31) on the same side; An annular groove (92) is provided at the interface of the outer wall of the retaining ring (91), the jacket housing (31) and the main body (1) of the airflow pulverizing device on the same side, and a sealing rubber ring (93) is inserted in it. The sealing ring (93) is located in the annular groove (92) and is in an elastic compression state.

6. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 1, characterized in that, The gas-to-gas heat exchange assembly (7) includes: The gas-to-gas heat exchanger (71) has its tube side inlet and outlet connected in series on the connecting pipe between the cyclone separator (5) and the bag filter (6); The shell-side inlet of the gas-to-gas heat exchanger (71) is connected to an external fan as a gas source; The shell-side outlet of the gas-to-gas heat exchanger (71) is fixedly connected to a connecting pipe (73), the end of which is fixedly connected to the input end of the second jacket (2).

7. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 6, characterized in that, The number of gas-to-gas heat exchangers (71) is at least two, and the gas-to-gas heat exchangers (71) are connected in series; The shell-side inlet of the gas-to-gas heat exchanger (71) is fixedly connected to an air inlet manifold (74), and the air inlet manifold (74) is connected to an external fan as an air source. The shell-side outlet of the gas-to-gas heat exchanger (71) is fixedly connected to an air outlet manifold (72), and the air outlet manifold (72) is fixedly connected to a connecting pipe (73).

8. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 3, characterized in that, The outer wall of the jacket shell (31) is covered with a thermal insulation material layer (35).

9. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 8, characterized in that, The thermal insulation material layer (35) is specifically an aerogel felt layer.

10. The low-temperature airflow pulverizing device for high-flow-rate nylon powder according to claim 4, characterized in that, The wear-resistant, hydrophobic, and oleophobic coating (34) is specifically a Teflon coating.

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